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Groups > comp.os.linux.networking > #708

Re: Only some IPs accessable?

Cross-posted to 2 groups.

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Henrik Carlqvist <Henrik.Carlqvist@deadspam.com> wrote:
>Now, when trying to recreate that I only got partial success. I have no
>DNS server running on localhost:
>
>-8<---------------------
>bash-3.1# cat /etc/resolv.conf
># Generated by dhcpcd for interface wlan0
>search Belkin
>nameserver 192.168.30.254

...

>bash-3.1# time nslookup www.google.com
>Server:         192.168.30.254
>Address:        192.168.30.254#53
>
>Name:   www.google.com
>Address: 209.85.169.105
>
>real    0m0.104s
>user    0m0.004s
>sys     0m0.004s

That is as expected.

>bash-3.1# emacs -nw /etc/resolv.conf
>bash-3.1# cat /etc/resolv.conf
># Generated by dhcpcd for interface wlan0
>search Belkin
>nameserver 192.168.30.254
>nameserver 127.0.0.1
>
>bash-3.1# time nslookup www.google.com
>;; Got recursion not available from 192.168.30.254, trying next server
>;; connection timed out; no servers could be reached
>
>real    0m15.113s
>user    0m0.004s
>sys     0m0.000s
>-8<---------------------

On my system the same configuration results in exactly
the same time as with only a single valid nameserver
entry.  If I put the invalid entry first it takes about
1 second longer.  I only get the 15 second time out if
there are no valid entries.

>In the example above "nslookup www.google.com" takes 0.1s with a single
>working nameserver in resolv.conf. Adding a broken nameserver increases
>that time to 15s and also gives no answer. This test was done on Slackware
>12.2.

I'm using Slackware 13.37, but have never seen it any different.

>The above example does not behave exactly as I remembered the problem, but
>at least it shows there is something fishy with nslookup.

Yep, that's downright weird!

-- 
Floyd L. Davidson                <http://www.apaflo.com/>
Ukpeagvik (Barrow, Alaska)              floyd@apaflo.com

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Thread

Only some IPs accessable? "NoHtmlMailsPlease" <UsePlainText@dog.edu> - 2011-10-07 22:42 +0200
  Re: Only some IPs accessable? Frank Boehm <fraboehm@gmx.de> - 2011-10-08 07:39 +0000
  Re: Only some IPs accessable? Chris Davies <chris-usenet@roaima.co.uk> - 2011-10-08 14:24 +0100
    Re: Only some IPs accessable? Ivan Shmakov <ivan@gray.siamics.net> - 2011-10-08 23:18 +0700
      Re: Only some IPs accessable? Chris Davies <chris-usenet@roaima.co.uk> - 2011-10-08 21:29 +0100
    Re: Only some IPs accessable? "NoHtmlMailsPlease" <UsePlainText@dog.edu> - 2011-10-12 15:09 +0200
      Re: Only some IPs accessable? Ralph Spitzner <rasp@spitzner.org> - 2011-10-12 17:24 +0200
        Re: Only some IPs accessable? Chris Davies <chris-usenet@roaima.co.uk> - 2011-10-13 10:55 +0100
      Re: Only some IPs accessable? Henrik Carlqvist <Henrik.Carlqvist@deadspam.com> - 2011-10-12 22:22 +0200
      Re: Only some IPs accessable? Chris Davies <chris-usenet@roaima.co.uk> - 2011-10-13 11:01 +0100
        Re: Only some IPs accessable? "NoHtmlMailsPlease" <UsePlainText@dog.edu> - 2011-10-14 23:00 +0200
          Re: Only some IPs accessable? Henrik Carlqvist <Henrik.Carlqvist@deadspam.com> - 2011-10-15 11:46 +0200
            Re: Only some IPs accessable? floyd@apaflo.com (Floyd L. Davidson) - 2011-10-15 04:59 -0800
              Re: Only some IPs accessable? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-10-15 16:39 +0000
                Re: Only some IPs accessable? floyd@apaflo.com (Floyd L. Davidson) - 2011-10-15 08:50 -0800
                Re: Only some IPs accessable? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-10-15 16:58 +0000
                Re: Only some IPs accessable? Richard Kettlewell <rjk@greenend.org.uk> - 2011-10-15 19:07 +0100
              Re: Only some IPs accessable? Henrik Carlqvist <Henrik.Carlqvist@deadspam.com> - 2011-10-15 19:50 +0200
                Re: Only some IPs accessable? floyd@apaflo.com (Floyd L. Davidson) - 2011-10-15 12:30 -0800
                Re: Only some IPs accessable? Ralph Spitzner <rasp@spitzner.org> - 2011-10-19 18:14 +0200

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